Recommendation ITU-R BT.1889(03/2011)

Common application environment for interactive digital broadcasting

services

BT SeriesBroadcasting service

(television)

ii Rec. ITU-R BT.1889

Foreword

The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted.

The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups.

Policy on Intellectual Property Right (IPR)

ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http://www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found.

Series of ITU-R Recommendations(Also available online at http://www.itu.int/publ/R-REC/en)

Series Title

BO Satellite deliveryBR Recording for production, archival and play-out; film for televisionBS Broadcasting service (sound)BT Broadcasting service (television)F Fixed serviceM Mobile, radiodetermination, amateur and related satellite servicesP Radiowave propagationRA Radio astronomyRS Remote sensing systemsS Fixed-satellite serviceSA Space applications and meteorologySF Frequency sharing and coordination between fixed-satellite and fixed service systemsSM Spectrum managementSNG Satellite news gatheringTF Time signals and frequency standards emissionsV Vocabulary and related subjects

Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1.

Electronic PublicationGeneva, 2011

ITU 2011

All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU.

Rec. ITU-R BT.1889 1

RECOMMENDATION ITU-R BT.18891

Common application environment for interactive digital broadcasting services(Question ITU-R 131/6)

(2011)

Scope

This Recommendation specifies a common application environment to be used for interactive digital broadcasting services.

The ITU Radiocommunication Assembly,

considering

a) the need to avoid protocols proliferating for interactive multimedia services;

b) that digital broadcasting services (satellite, terrestrial, and cable) are becoming widely available and offer multimedia applications;

c) that multimedia applications have been developed that comprise video, audio, still picture, text, graphics, etc. associated with interactive features;

d) that multimedia applications planned or deployed in some regions are using the executable application environment as described in Recommendation ITU-R BT.1722;

e) that multimedia applications planned or deployed in some regions are using the declarative application environment as described in Recommendation ITU-R BT.1699;

f) that Recommendation ITU-T J.200 defines the worldwide common core of application environment for digital interactive television services;

g) that the ITU-R and ITU-T Sectors are continuously working and reviewing Application Programming Interfaces (APIs);

h) that common application environment for interactive TV applications is desirable for production and international exchange of multimedia content,

recommends

1 that Recommendation ITU-T J.200 should be used as the application environment for interactive digital broadcasting services.

NOTE 1 – Appendix of this Recommendation summarizes Recommendation ITU-T J.200 for information.

1 This Recommendation should be brought to the attention of ITU-T Study Group 9.

2 Rec. ITU-R BT.1889

Appendix(Informative)

Summary of Recommendation ITU-T J.200

1 Overview

Recommendation ITU-T J.200 – Worldwide common core – Application environment for digital interactive television services, consists of basic architecture of the environment, structure of execution engine, and structure of presentation engine.

2 Abbreviations

API Application programming interface

BML Broadcast markup language

CA Conditional access

CSS Cascading style sheet

DOM Document object model

GUI Graphical user interface

HTML Hyper text markup language

JMF Java media framework

LWUIT Light-weight user interface toolkit

MHEG Multimedia and hypermedia expert group

MIME Multipurpose internet mail extensions

NCL Nested context language

UI User interface or user interaction

XHTML Extensible hyper text markup language

XML Extensible markup language

3 Basic architecture

The high-level architecture of APIs and middleware for digital interactive TV can be regarded as essentially comprising two components: the execution engine and the presentation engine. However, these two components are not necessarily independent; appropriate bridges may be defined. In addition to the basic components, there will be other native applications, or service-specific software and content, such as MHEG, as well as various proprietary formats.

Figure 1 shows the structure of the application environment. It identifies the relationship between the presentation engine and the execution engine.

Rec. ITU-R BT.1889 3

FIGURE 1Application environment basic system architecture

1. Presentation engine/execution engine – These are major components to handle interactive TV applications and are both required. The presentation engine handles declarative TV applications such as HTML and BML content. The execution engine is a processor that executes interactive TV applications. It is recognized that, in some cases, one or the other has been implemented individually. However, to achieve full harmonization and worldwide interoperability of applications, both execution engine and presentation engine are required.

2. Bridge elements – This is a mechanism for applications that allows bidirectional mapping between the execution engine and presentation engine.

3. App lifecycle monitor – This controlling software is expressed differently in each specification. It can appear as a full-fledged application or just a simple OS monitor to control the state of the software. The general functionality is to manage applications over its entire life cycle, including initiation, termination, and control.

4. Applications – In some systems these applications can be limited to service-bound applications or unbounded applications. These applications can be written either to the presentation, the execution, or both.

5. User interaction – This is the input layer into remote control, keyboards, and other controllers.

6. Other media – This media includes streaming media such as audio and data feeds or monomedia such as static images and text.

7. Native software – This is software that is either legacy software or software written using additional APIs and functionality outside the specified application environment.

Application Application Application Application

Bridge elementsExecution engine Presentation engine

Network CA GUI presentation Broadcast eventsand Data

Digital video(MPEG)

Other media

Operating system

Hardware

Nativesoftware

App lifecycle monitor

T0910150-00

User interaction

Application

Serviceinformation (etc.)

4 Rec. ITU-R BT.1889

4 Execution engine

Figure 2 shows the structure of the execution engine and indicates the origin of the various elements.

FIGURE 2Structure of execution engine

Key standards that should be supported by the execution engine are:1. Basic Java Functionality – This APIs consists of the personal basis profile, foundation

profile and connected device configuration.2. Extensions for Broadcasting – This API consists of the javax.tv.* packages as specified by

Sun Microsystems in the JavaTV specification plus additional broadcasting functionalities such as section filtering, transport stream tuning, resource management, and return channel connectivity management (e.g. DAVIC or Ginga-J).

3. Presentation extension for media – This API consists of the javax.media.* packages by Sun Microsystems.

4. UI extensions for TV – This API provides TV specific functionality for presentation and user interaction e.g. HAVi UI API or LWUIT.

5. Extensions for access to service information and network protocol (e.g. relevant APIs defined in DVB-MHP, OCAP, ACAP, ARIB STD-B23, GINGA-J).

5 Presentation engine

Figure 3 shows the structure of the presentation engine and indicates the origin of the various elements.

Extensions for a network protocolccess to service information and

Extension for broadcasting (such as selection of TS packets,section filtering, resource management, etc.)

(JAVA TV API etc.)

for mediaPresentation extensionJMF (Java Media Framework)

UI extensions for TVcontrol

Basic Java Functionality

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FIGURE 3Structure of presentation engine

The key standards that should be supported by the presentation engine are as follows:1. Markup language such as HTML, BML and NCL Common modules defined in XHTML

Modularization and/or HTML as defined by W3C.2. CSS style sheet to describe presentation style as defined by W3C.3. DOM APIs to dynamically change the contents of HTML or XHTML documents as

defined by W3C.4. Scripting language.5. NCL as declarative glue language. 6. TV Specific Extensions and additional APIs and DOM Objects for handling signalling,

triggers, protocols, and MIME types specific to TV receivers and receiver-specific functions.

7. Standard media types such as image/jpg, image/png, audio/basic and TV specific media types such as video/mpeg as defined by ISO.

8. XML parser as defined by W3C.

Scripting language(ECMAScript, Lua …)

Document style(CSS, …)

Document interface(DOM, language specific …)

Markup language(HTML, BML, NCL …)

TV extensions

Declarative glue language (optional)XML parser

Receiver functionality Digital video(MPEG) Monomedia Network

User agent (browser)